Changes in seizure susceptibility in rats following chronic administration of pentylenetetrazol.

Abstract

Repeated administration of pentylenetetrazol (PTZ) once every 48 h in behaviourally active threshold and suprathreshold doses induces a marked enhancement of seizure behaviour (kindling phenomenon). In contrast, PTZ in initially subconvulsive doses failed to elicit convulsions more complex than stage 1 seizures. With 40 mg/kg PTZ i.p. kindled rats show in the fully kindled state a marked shift of the dose-response curve for PTZ-seizures to the left. The mean stage 4 dose of PTZ is 40 mg/kg in kindled and 75 mg/kg in non-kindled rats.